Commit 85e034fd authored by Larry Finger's avatar Larry Finger Committed by Greg Kroah-Hartman
Browse files

USB: Check results of dma_map_single 

In map_urb_for_dma(), the DMA address returned by dma_map_single()
is not checked to determine if it is legal. This lack of checking
contributed to a problem with the libertas wireless driver
(http://marc.info/?l=linux-wireless&m=125695331205062&w=2

). The
difficulty was not detected until the buffer was unmapped. By this time
memory corruption had occurred.

The situation is fixed by testing the returned DMA address, and
returning -EAGAIN if the address is invalid.

Signed-off-by: default avatarLarry Finger <Larry.Finger@lwfinger.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 796c8c78

drivers/usb/core/hcd.c

+10 −4
Original line number Diff line number Diff line
@@ -1275,13 +1275,16 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, 


	if (usb_endpoint_xfer_control(&urb->ep->desc)

	    && !(urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {

		if (hcd->self.uses_dma)

		if (hcd->self.uses_dma) {

			urb->setup_dma = dma_map_single(

					hcd->self.controller,

					urb->setup_packet,

					sizeof(struct usb_ctrlrequest),

					DMA_TO_DEVICE);

		else if (hcd->driver->flags & HCD_LOCAL_MEM)

			if (dma_mapping_error(hcd->self.controller,

						urb->setup_dma))

				return -EAGAIN;

		} else if (hcd->driver->flags & HCD_LOCAL_MEM)

			ret = hcd_alloc_coherent(

					urb->dev->bus, mem_flags,

					&urb->setup_dma,
@@ -1293,13 +1296,16 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, 
	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;

	if (ret == 0 && urb->transfer_buffer_length != 0

	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {

		if (hcd->self.uses_dma)

		if (hcd->self.uses_dma) {

			urb->transfer_dma = dma_map_single (

					hcd->self.controller,

					urb->transfer_buffer,

					urb->transfer_buffer_length,

					dir);

		else if (hcd->driver->flags & HCD_LOCAL_MEM) {

			if (dma_mapping_error(hcd->self.controller,

						urb->transfer_dma))

				return -EAGAIN;

		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {

			ret = hcd_alloc_coherent(

					urb->dev->bus, mem_flags,

					&urb->transfer_dma,

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